It might have come to mind to everyone by now, that its only the sun that net contributes to our earth, in the form of solar energy. All other options deplete the system from inside, and come with nasty side effects. It requires no rocket science to figure out that at some point we will be completely dependent of Solar energy.
Knowing that, you would expect that the sun takes a central role in anything we do, and especially in how we organise our built environment, our land planning. In the long run its of live saving importance to optimise the use of solar radiation. Which we already new back in the eighties, for instance in architecture, but houses and buildings are still designed as if that is completely irrelevant. The building sector, architects , project developers, urban planners, all neglect this relation more or less. ‘Others will solve energy and climate crises’, seems the general thought. But we will need every m2 , to have but any chance to develop a renewable energy supply system, to maintain some level of welfare, and avoid that climate change creates a global chaos.
There are discussions on ways to stop climate change. Since bottom up did not work, its top down this time, like for instance giving CO2 credits to civilians: directly , maximized, or via a CO2 tax. Which might work, but will not be sufficient. Since demand for free or low CO2 energy will increase and it will be of major importance to manage space optimally to profit from Solar radiation. Which requires additional measures: that of each and everyones legal rights to the sun . Besides CO2 credits, each of us should be entitled to a fair share of Solar radiation. Its just like ‘commons’, when people jointly manage land. But now its the space above, kind of ‘commons high’, or Solar commons’ . It came very close again last week, as a friend showed me the graph of his daily output from his solar panels. The graph suddenly dropped during a sunny midday , since the neighbor on the south side has a tree in his garden, which grows higher and higher. It twas what triggered me to write about this , again.
The graph will look familiar to many Solar panels owners, I guess. But its of course ridiculous, The owner of the tree has to be forced to maintain it and keep it below a certain level, within a guaranteed ‘free solar access’ level for his backyard-neighbor so to say.
I am waiting for the first neighbors going to court over this. I took the opportunity to look what our law says about this . The Dutch book of civilian law, in part 3 article 20 describes ownership of land and buildings, but its article 21 that explains what we want to know:
Art 21 section 1: The competence of the owner of the land to use this, includes the competence of use of the space above and below the surface.
And section 2 adds:
The use of the space above and below the surface is permitted to others, providing it is that high or low of the surface that the owner has no interest in contesting this.
( I hope my English is good enough for translating legal texts…)
Anyway, this seems to help : in this case the hight of the tree is high enough for others to contest this . The problem however is, that below and above are nowhere defined… a judge will interpret above and below as if perpendicular to the surface, right angles. Which will work if we want to catch rainwater, to use and save on drinking water, but fails with catching solar radiation. And Solar radiation, being of of life saving importance for society , comes in at an angle. Above and below should be detailed defined in law, and according location of course, since the angle is different depending latitude. The drawing shows how this works out for a house: from the land boundary, lines have to be drawn following highest an lowest solstice, which defines space where and where not can be built , or ‘ space occupied’ . 
Which implies that ‘ right to sun” requires a different approach in spatial planning and design. Planners and architects always start from a perpendicular perspective, and this way neglect the most important guiding feature, being solar radiation. ( not only for energy but also for daylight)
There are many examples of houses , even some that have been designed for Solar energy production, that ended up overshadowed by buildings south of them. And the law should address these issues.
Its by the way not only relevant at building or Urban level. Also on national level this can become of importance: The lines can be similarly drawn from countries borders, limiting neighbors to built where it can overshadow beyond the border. Which is not completely superficial, when thinking of geo-technical solutions discussed to tackle climate change. As for instance bringing immense umbrellas in space. When above Belgium these could shadow the Netherlands. Or better: If the Dutch would want to apply these umbrellas, they should hang above Belgium…. ( but I hope no one will be stupid enough to try this) So also on national level: The territorial area is not right above, but follows solar solstice. Compare this with nuclear radiation after a melt down, which will affect cross border, or smell of pig farms, which spread in all directions. ( for which the Netherlands has a law defining maximum “odor smell circles”! )
With climate change in mind, and the Sun as our only hope, its about time the law will reflect this, define ‘ above” as following the solar solstice, and give everyone a clear window on Solar radiation.
: Rovers R., 2013, Urban and building dynamics: a 3D (exergy) approach required, 3rd International Exergy, Life Cycle Assessment, and Sustainability Workshop & Symposium (ELCAS3) 07 -09 July, 2013, GREECE
PS After posting this blog I received an interesting article with similar problems with high rise buildings shadowing each other from England: page 26: https://lnkd.in/gyDGKaU